﻿using Microsoft.Windows.Shell;
using System;
using System.Runtime.InteropServices;
using System.Windows;
using System.Windows.Input;
using System.Windows.Interop;

namespace HeaderWindow
{
    public class UserWindow : Window
    {

        /// <summary>
        /// Initializes the metadata for the window
        /// </summary>
        static UserWindow()
        {
            DefaultStyleKeyProperty.OverrideMetadata(typeof(UserWindow), new FrameworkPropertyMetadata(typeof(UserWindow)));
        }

        public UserWindow()
        {
            // 显示系统菜单项
            CommandBinding ShowSystemMenuCmdBinding = new CommandBinding(SystemCommands.ShowSystemMenuCommand, onShowSystemMenuCommand);
            // 关闭窗体命令
            CommandBinding CloseWindowCmdBinding = new CommandBinding(SystemCommands.CloseWindowCommand, onCloseWindowCommand);

            // 绑定路由命令
            this.CommandBindings.Add(ShowSystemMenuCmdBinding);
            this.CommandBindings.Add(CloseWindowCmdBinding);

            RepariWindow.RepairWindowBehavior(this);
        }

        #region DependencyProperty

        public FrameworkElement TitleElement
        {
            get { return (FrameworkElement)GetValue(TitleElementProperty); }
            set { SetValue(TitleElementProperty, value); }
        }
        public static readonly DependencyProperty TitleElementProperty =
            DependencyProperty.Register("TitleElement", typeof(FrameworkElement), typeof(UserWindow), new PropertyMetadata(null));

        public double ResizeBorderThickness
        {
            get { return (double)GetValue(ResizeBorderThicknessProperty); }
            set { SetValue(ResizeBorderThicknessProperty, value); }
        }
        public static readonly DependencyProperty ResizeBorderThicknessProperty =
            DependencyProperty.Register("ResizeBorderThickness", typeof(double), typeof(UserWindow), new PropertyMetadata(5d));

        public double CaptionHeight
        {
            get { return (double)GetValue(CaptionHeightProperty); }
            set { SetValue(CaptionHeightProperty, value); }
        }
        public static readonly DependencyProperty CaptionHeightProperty =
            DependencyProperty.Register("CaptionHeight", typeof(double), typeof(UserWindow), new UIPropertyMetadata(25d));

        public CornerRadius CornerRadius
        {
            get { return (CornerRadius)GetValue(CornerRadiusProperty); }
            set { SetValue(CornerRadiusProperty, value); }
        }
        public static readonly DependencyProperty CornerRadiusProperty =
            DependencyProperty.Register("CornerRadius", typeof(CornerRadius), typeof(UserWindow), new UIPropertyMetadata(default(CornerRadius)));

        #endregion

        private void onCloseWindowCommand(object sender, ExecutedRoutedEventArgs e)
        {
            Window window = Window.GetWindow(this);
            SystemCommands.CloseWindow(window);
        }

        private void onShowSystemMenuCommand(object sender, ExecutedRoutedEventArgs e)
        {
            Window window = Window.GetWindow(this);

            Point point = new Point(window.Left + 29, window.Top + 29);
            if (window.WindowState == System.Windows.WindowState.Maximized)
            {
                point = new Point(24, 24);
            }

            SystemCommands.ShowSystemMenu(window, point);
        }

    }
}

internal class RepariWindow
{
    public static void RepairWindowBehavior(Window wpfWindow)
    {
        if (wpfWindow == null)
            return;

        wpfWindow.SourceInitialized += delegate
        {
            IntPtr handle = (new WindowInteropHelper(wpfWindow)).Handle;
            HwndSource source = HwndSource.FromHwnd(handle);
            if (source != null)
            {
                source.AddHook(WindowProc);
            }
        };
    }

    private static IntPtr WindowProc(IntPtr hwnd, int msg, IntPtr wParam, IntPtr lParam, ref bool handled)
    {
        switch (msg)
        {
            case 0x0024:
                WmGetMinMaxInfo(hwnd, lParam);
                handled = true;
                break;
        }

        return (IntPtr)0;
    }

    private static void WmGetMinMaxInfo(IntPtr hwnd, IntPtr lParam)
    {
        MINMAXINFO mmi = (MINMAXINFO)Marshal.PtrToStructure(lParam, typeof(MINMAXINFO));

        int MONITOR_DEFAULTTONEAREST = 0x00000002;
        IntPtr monitor = MonitorFromWindow(hwnd, MONITOR_DEFAULTTONEAREST);

        if (monitor != IntPtr.Zero)
        {
            MONITORINFO monitorInfo = new MONITORINFO();
            GetMonitorInfo(monitor, monitorInfo);
            RECT rcWorkArea = monitorInfo.rcWork;
            RECT rcMonitorArea = monitorInfo.rcMonitor;
            mmi.ptMaxPosition.x = Math.Abs(rcWorkArea.left - rcMonitorArea.left);
            mmi.ptMaxPosition.y = Math.Abs(rcWorkArea.top - rcMonitorArea.top);
            mmi.ptMaxSize.x = Math.Abs(rcWorkArea.right - rcWorkArea.left);
            mmi.ptMaxSize.y = Math.Abs(rcWorkArea.bottom - rcWorkArea.top);
        }

        Marshal.StructureToPtr(mmi, lParam, true);
    }

    [DllImport("user32")]
    internal static extern bool GetMonitorInfo(IntPtr hMonitor, MONITORINFO lpmi);
    [DllImport("User32")]
    internal static extern IntPtr MonitorFromWindow(IntPtr handle, int flags);

    #region Nested type: MINMAXINFO
    [StructLayout(LayoutKind.Sequential)]
    internal struct MINMAXINFO
    {
        public POINT ptReserved;
        public POINT ptMaxSize;
        public POINT ptMaxPosition;
        public POINT ptMinTrackSize;
        public POINT ptMaxTrackSize;
    }
    #endregion

    #region Nested type: MONITORINFO
    [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
    internal class MONITORINFO
    {
        public int cbSize = Marshal.SizeOf(typeof(MONITORINFO));
        public RECT rcMonitor;
        public RECT rcWork;
        public int dwFlags;
    }
    #endregion

    #region Nested type: POINT
    [StructLayout(LayoutKind.Sequential)]
    internal struct POINT
    {
        public int x;
        public int y;
        public POINT(int x, int y)
        {
            this.x = x;
            this.y = y;
        }
    }
    #endregion

    #region Nested type: RECT
    [StructLayout(LayoutKind.Sequential, Pack = 0)]
    internal struct RECT
    {
        public int left;
        public int top;
        public int right;
        public int bottom;

        public static readonly RECT Empty;

        public int Width
        {
            get { return Math.Abs(right - left); }
        }
        public int Height
        {
            get { return bottom - top; }
        }

        public RECT(int left, int top, int right, int bottom)
        {
            this.left = left;
            this.top = top;
            this.right = right;
            this.bottom = bottom;
        }

        public RECT(RECT rcSrc)
        {
            left = rcSrc.left;
            top = rcSrc.top;
            right = rcSrc.right;
            bottom = rcSrc.bottom;
        }

        public bool IsEmpty
        {
            get
            {
                return left >= right || top >= bottom;
            }
        }

        public override string ToString()
        {
            if (this == Empty)
            {
                return "RECT {Empty}";
            }
            return "RECT { left : " + left + " / top : " + top + " / right : " + right + " / bottom : " + bottom + " }";
        }

        public override bool Equals(object obj)
        {
            if (!(obj is Rect))
            {
                return false;
            }
            return (this == (RECT)obj);
        }

        public override int GetHashCode()
        {
            return left.GetHashCode() + top.GetHashCode() + right.GetHashCode() + bottom.GetHashCode();
        }

        public static bool operator ==(RECT rect1, RECT rect2)
        {
            return (rect1.left == rect2.left && rect1.top == rect2.top && rect1.right == rect2.right && rect1.bottom == rect2.bottom);
        }

        public static bool operator !=(RECT rect1, RECT rect2)
        {
            return !(rect1 == rect2);
        }
    }
    #endregion
}